This disclosure relates to novel tertiary alkyl, cycloalkyl or aralkyl azo compounds containing an .alpha.-tertiary aliphatic peroxy group as represented by the formula ##STR4## to processes for their preparation and to their use as polymerization initiators for vinyl monomers and as curing agents for polyester resin compositions.
To the best of applicants' knowledge, no azo-peroxides of structure I have been previously reported, though the combination of azo and peroxide groups in the same molecule is disclosed in U.S. Pat. No. 3,282,912 and Canadian Pat. No. 750,380 (structures VII and VIII, respectively): ##STR5## The VII compounds are symmetrical azo compounds and thus fall into a completely different category from the compounds of the instant case. The VIII compounds also differ significantly in structure since R" of the compounds (I) of the instant invention does not include cyano or other functional groups which could create toxicity problems.